1. Field of the Invention.
The present invention relates generally to receivers for solar energy, and more particularly to a receiver having a solar radiation transparent enclosure with an enlarged end portion and articulated for movement relative to a fixed, substantially fixed spherical concave collector for concentrating solar energy on the receiver.
2. Description of the Prior Art.
Systems for collecting and concentrating solar energy are known. Generally, such systems involve a relatively large reflective concave collector which is articulated to track the sun and focus the reflective solar energy on a fixed receiver relative to the collector.
However, another particularly advantageous system exists in which a large, fixed concave substantially truncated spherical section collector is utilized to reflect concentrated solar energy onto a receiver which moves relative to the fixed collector. Thus as the sun moves, the position of the focused solar energy also moves relative to the fixed collector and is tracked by the movable receiver. An example of such a system is to be found in French Pat. No. 635,283 issued Dec., 1927 to Berland. Such systems conventionally utilize receivers which absorb solar energy and means within the enclosure through which a heat transfer media is circulated. Since temperatures on the order of 500.degree. F., or higher, can be obtained, it is of course important to minimize energy losses. Also, since the collector is necessarily large, it is not a precision ground surface and, thus, though theoretically a small receiver will suffice, it has been found necessary to present a relatively large target for the reflected solar energy in view of aberrations resulting from imperfection in the nominally spherical collecting surface.
Conventional receivers, however, have now been found to be compromised in efficiency as a result of the unique requirements of the system utilized an articulated receiver in conjunction with a fixed collector.